Local growers and ag officials work to increase awareness of citrus-killing insect

May 20, 2016

AUBURN, Calif. -- It’s a small insect the size of a grain of rice that by itself is fairly innocuous. But the Asian citrus psyllid is capable of carrying a bacteria that will kill every citrus tree it infects.

A large-scale infestation can be devastating. Both the insect and the disease have been discovered in a handful of home citrus trees in Southern California and pose no immediate threat to Placer County. However, local citrus growers and agricultural officials both here and throughout the state are carefully watching.

The psyllid can carry Huanglongbing disease, HLB, also known as citrus greening disease. The psyllid has been found as far north as San Joaquin County, but so far HLB has only been found in Los Angeles County. The insects infest citrus trees by laying larvae into new growth. If the psyllid carries the disease, the tree will slowly die, though symptoms will not show up for several years.

“The concern for Placer County, and our world-renowned mandarins, is people unknowingly transporting the Asian citrus psyllid into the county,” said Agricultural Commissioner Joshua Huntsinger. “The psyllid can only fly a short distance and is almost always spread by people transporting infested plants or plant material.”

Placer County wants to increase the public’s awareness of not only what the disease can do, but how to avoid bringing it to the foothills.Transporting citrus trees, rootstock or fruit with attached leaves can give the psyllid the avenue to bring disease to our citrus trees.

The agricultural commissioner’s office has increased surveillance for the psyllid and is reminding everyone of the importance of not moving citrus trees or fruit into the county from other locations. The office also is asking the public to only buy citrus trees and root stock from reputable, licensed nurseries and to cooperate with county staff who do inspections.

Placer County has a robust inspection program. The county agricultural commissioner’s office has traps placed in about 40 commercial groves, in addition to 220 traps in urban and residential trees. All incoming shipments of citrus trees going to nurseries for retail sale are inspected, as are trees going to growers who are planting or augmenting existing orchards.